This invention relates to novel intermediate compounds resulting from a method for forming a dihydrogen-phosphate inositol from a protected or unprotected inositol that comprises at least two vicinal trans hydroxy groups that are unprotected. This method results in each of the unprotected hydroxy groups of the inositol, which can contain from two to six unprotected hydroxy groups, being converted to a dihydrogen-phosphate group and each protected group being converted to a free hydroxy group. The method permits one to make such compounds in very few steps and in very high yields.
Specifically, the method is useful for making myo-inositol 1,4,5-trisphosphate, myo-inositol 1,3,4-trisphosphate, myo-inositol 2,4,5-trisphosphate, myo-inositol 1,3,4,5 tetrakisophosphate and deuterium and tritium labelled derivatives thereof. Such compounds, which exist in nature, have been referred to as "second messengers".
One of the control mechanisms for regulation of intracellular Ca.sup.2+ ion concentration involves activation of membrane receptors followed by signal transduction and the release of a modulatory substance. Recent studies provide compelling evidence that activation of these Ca.sup.+2 mobilizing receptors results in hydrolysis of phosphatidyl-inositol-4,5-biphosphate, giving rise to D-myo-inositol-1,4,5-trisphosphate (IP.sub.3). IP.sub.3 directly mediates release of calcium from intracellular stores. For an excellent review of second messengers and their function see Berridge, "The Molecular Basis of Communication within the Cell", Scientific American, October, 1985 and Berridge et al., "Inositol Trisphosphate, a Novel Second Messenger in Cellular Signal Transduction", Nature, Vol. 312, Nov. 22, 1984.
It is desirable to utilize the second messengers in order to analyse their biochemical pathways within the cell and to analyse the effects of the second messengers on cells. Also, it would be desirable to label the second messengers, which would assist one in establishing a competitive binding assay to determine whether or not other compounds are capable of binding to the second messenger receptors. However, very small quantities of the second messengers are produced naturally. Thus, it would be highly desirable to produce them synthetically.
Numerous attempts have been made to synthesize the inositol second messengers. However, all of the methods have resulted in the final product being produced in very low yields. Such low yields are primarily caused by the difficulty of adding a dihydrogen phosphate group to the vicinal trans hydroxy group(s) of inositol. For example, see S. J. Angyal et al, "Polyphosphorylation of Polyols, the Synthesis of Myo-Inositol Pentaphosphates," Aust. J. Chem., 1968, 21, pp. 391-404; V. N. Krylova et al., "Investigations in the Field of Derivatives of Asymmetrically Substituted Myo-inositol", Zhurnal Organicheskoi Khimii, Vol. 16., No. 2, pp. 315-322, February, 1980; and Ozaki et al., "Total Synthesis of Optically Active Myo-Inositol 1,4,5 Tris(phosphate)", Tetrahedron Letters, Vol. 27, No. 27, pp. 3157-3160, 1986.